This invention relates to cat litter boxes and pet toilets which are attachable to a conventional toilet bowl, specifically to a simplified and easy to use cat litter box comprising an oval support member configured for attachment to the inside surface of a conventional toilet bowl, a removable tray slidably inserted through an opening in the front side of the oval support member which is configured to cover the toilet bowl opening and upon which flushable cat litter is placed during use, and stationary teeth attached to the inside front surface of the oval support member which engage the upper surface of the removable tray as it is slidably withdrawn from the front opening to empty used flushable cat litter directly into the toilet bowl for flushing.